


Shivering Soul

by b0o



Category: Undertale (Video Game)
Genre: Alternate Universe - Underfell, F/M, Mpreg, Sans Needs A Hug, mentioned relationship, skelepreg
Language: English
Status: In-Progress
Published: 2016-06-17
Updated: 2016-07-04
Packaged: 2018-07-15 15:00:53
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 2,543
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7227157
Author URL: https://archiveofourown.org/users/b0o/pseuds/b0o
Summary: <blockquote class="userstuff">
              <p>Underfell! Sans tries to hides his pregnancy from Papyrus, nothing goes the way it should.</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

> The plot bunny beckons.

At his sentry station in Snowdin Sans gently ran a hand over his stomach, feeling the still small soul move slightly. The conflicting feelings of happiness and fear take their place at the center in his own soul. 

In this world it was kill or be killed and an expecting monster was always going to be a target because of their weakened magic and the amount of Exp they gave off was higher. 

He was already an easy target in most monsters eyes with his 1 Hp, but they usually restrained themselves in fear of being dusted by his brother. 

The thought of his brother had him wrap his arm around his stomach protectivly, he had kept it from his brother for this long and was truly afraid of how he would react. 

Papyrus had never hid his dislike for the shorter skeleton and Sans knew that it was only a matter of time before he either attacked or abandoned him.

Sans lied his head down and started drifting away, no matter how much he ate or slept his magic just couldn’t keep up with how much the kid was taking and everyday was getting harder to keep going.

Red eyes glared down at him. “You've always been weak and pathetic but this is truly a new low for you. What makes you think you can raise a child when you failed so miserably at providing even the basics for me all those years? I killed countless monsters in order to survive because you couldn't do a damn thing but sit on your ass and wallow in self-pity. Do you truly think that pitiful goat will do anything but take the child as soon as she can and run as far away from you as possible? How could you possibly believe any sane monster could love you? I’ve wasted enough time on you, the only thing you can be useful at is getting me to the next Level.” Bones appeared in every direction but Sans found himself unable to so much as move and could only let out a strangled yell when the bones rushed towards him.

A hand slamming down on the table made him jump and when he saw those familiar red eyes glaring down at him he reacted on pure impulse. 

Turning his younger brother’s soul blue he suspended him slightly off the ground, “i won’t let you kill them!!” 

Papyrus was stunned at what had just happened but quickly became angry, “FOR THE LOVE OF- IT WAS A DREAM SANS! NOW PUT ME DOWN IMMEADITLY, IDIOT!”

Coming out of his daze Sans stared at his brother and more importantly his hold on him, his legs began to tremble and he took a step back. 

“oh god, boss i- i’m so sorry. I didn’t mean to.” He tried to take another step back but his legs gave out and he landed heavily in the snow, however he was careful to keep his brother suspended.

At any other time Papyrus would be swearing and promising all kinds of punishments for the smaller skeleton, after all he was the captain of the royal guard and had a reputation to protect.

Yet when he looked at his brother, gasping for breath, trembling and a moment away from passing out he couldn’t voice a single threat.

“PUT ME DOWN BEFORE YOU PASS OUT AND EMBARESS YOURSELF FURTHER.” He felt the hold on his soul waver and weaken but the way his brother was shaking told him it wasn’t on purpose.

It was obvious to him this was more than the result of a bad nightmare, even his worst ones resulted in some broken furniture but not much else, and for the past few months he had seen less and less of his brother.

Sans could be skittish at times but he had never actually lashed out at him, despite how much he tried to provoke him to do so. 

Instead of feeling proud his older brother was finally fighting back he felt an odd but familiar emotion he couldn't immediately recognize worm its way around his soul.

Sans could feel his magic draining quickly but it wasn’t until his vision began to double that he realized just how bad it had gotten. 

He let his hold on his brother go and fell back into the cool snow, hopefully his brother would give him a small mercy and end it all quickly. 

Papyrus landed a bit harshly on his feet when his soul was dropped, and in an instant he was beside his brother who for his part didn’t seem to realize he was that close.

The taller skeleton recognized the old emotion as fear and now found himself trying to swallow it as he gently raised his brother onto his lap. 

He shakily conjured a weak healing magic, something he hadn’t done in a long time, he quickly glanced around just in case any monster had come close. 

A small groan had him concentrating back on his task and scowling furiously, he had overheard a rumor that his brother was sick and for most monsters that was practically a dinner bell so he naturally had to investigate himself.

Papyrus studied his older brother and was inclined to believe the rumor, his brother looked moments away from falling and was obviously having trouble with his magic.

Despite not having worked healing magic in years it seemed to be working, Sans’s breathing had leveled out and his face was no longer contorted in pain. 

Sans let out a small grumble and groggily rubbed his stomach before slipping off into sleep once more. The action struck Papyrus as odd and upon closer inspection his stomach seemed to distend further than-.

No.

He could deal with his brother being sick and stubborn but hoped that Sans wouldn’t have tried to go outside without him if he was…

Papyrus couldn’t finish the thought and reached down to gently grab the bottom of the red shirt. It was surprisingly hard for him to find the courage to lift it up and when he did he was greeted with a bright red ectostomach, immediately he focused on what was resting at the center of it and almost jumped when the small soul move slightly. 

He tugged the shirt back down and became still while his mind raced with what he saw. Anger rose quickly, for his brother on not informing him immediately and towards Toriel who was safe in that pitiful dimension of hers. 

Though he wouldn't admit it he felt relieved that he now knew his brothers secret and was actually going to be able to help.

It was only a matter of time before other monsters figured it out and if he wasn’t on his toes then his brother didn’t stand a chance.

He clenched a fist when he finally admitted what he needed to do and scooped up his brother. Holding him close to his chest Papyrus drew himself up to his full height and began a steady march to their home.

The moment he saw a monster he called forth dozens of his bones, when he entered town he summoned more but continued his determined pace and continued looking forward.

It was a generally unspoken rule that if you messed with Sans that you would be in for a bad time, but this was the farthest the taller had gone to show that he would kill anyone who so much as looked at his brother for too long.

When they were finally inside Papyrus made sure to lock the door before waving away his bones and laying Sans down on the couch.

Retrieving a spare blanket Papyrus did his best to position it so the other would feel warm but not trapped, the way Sans did when he used to tuck him in.

Sadly he had never actually watched what his older brother did and so his attempt ended with the blanket firmly trapping San’s arms and one leg was left uncovered.

While a part of him did want to fix that Papyrus knew that if he tried to do anything it would only result in his brother waking up.

For once unsure of what to do he patted the others head lightly before sitting on the floor next to the couch.  
When his brother woke up and recovered a bit they were going to have a very long talk.


	2. Chapter 2

**Summary for the Chapter:**

> Papyrus tries but is emotionally confused.

**Notes for the Chapter:**

> Aaaahhhh! I love the feedback! Thank you all so much!

Papyrus paced in front of the still sleeping Sans and paused when he heard the couch shift but saw that his brother was only moving in his sleep. Red eyes found the covered stomach and his pacing began anew. How would he be able to protect his brother against monsters now? 

Sans would need a considerable amount of magic from him and that wasn’t even taking into account when the soul would split. His scowl deepened at the thought and he rubbed his eye sockets angrily, the past however long Sans had been that low on magic would come back later to bite him. 

If Sans had told him immediately he could have set up a stable supply of magic. He stopped once again and his shoulders dropped, his brother had been too scared to ask for help and would rather die than show him weakness.

The realization had his soul throb painfully and he stared at the floor. “HAVE I REALLY BEEN THAT TERRIBLE OF A BROTHER?” He hadn’t meant to say it out loud and tried not to think about it for too long, after all if he started to doubt himself now then he would never be able to stay strong. 

Yet the question lingered, he had always been harsh and violent with his brother to try and toughen him up. Though the opposite had occurred and now the only one who had ever given a damn about him was terrified of him. 

He was torn out of his thoughts by a small grunt from his brother and he didn’t need to look to know that the smaller skeleton would be awake soon. Papyrus felt his soul pulse in nervousness and at any other time he would be disappointed he could still feel that emotion. 

Now however he stared how his brother was beginning to move around and he tried to hold down a thought long enough for it to become a plan. 

The last time he was next to Sans when he awoke had almost killed himself just trying to subdue the other. On the other hand if Sans woke up to an empty house he might try to teleport and would end up burning his magic up that way on top of being in some odd place. 

Papyrus scowled and let out a huff, all about that magic he knew his brother could teleport and that it wore him out. He didn’t know he far he could go, how much energy it used, if he could take someone else or if it had any serious negative effects. 

When his brother moved again he decided that a peace offering might be the best approach until he make sure his brother wouldn’t use magic. 

He found the nicest cup they owned, it only had one chip, and filled it with cold water. He set it down on and the coffee table in front of Sans and after a minute of deliberation sat on the other side of the table. 

Papyrus hated being lower than anyone and his impressive height meant it wasn’t usually a problem for him. Now however he didn’t want to intimidate his already on edge brother and the others small stature made it difficult to be on eye level at any time. 

Sans felt like his head was seconds away from just becoming dust and his body felt like lead. Part of him just wanted to lay there and give up but the louder voice was trying to say he needed to get up and move. 

Cracking his left eye open he closed it with a groan at how bright everything was, he tried kicking off the blanket but only managed to get a leg helplessly trapped. 

Opening his eye again he didn’t see the familiar wall of his room but instead saw a crouching blur of red and black. Running his hand over his eyes he felt a small nudge in stomach and his instincts screamed at him to run now.

He quickly sat up despite the general soreness and felt his soul drop when he saw his brother. The events from before flashed through his mind and he tried to find enough magic within to teleport before the calm broke. 

Papyrus pointed to the water, internally cringing at how his brother jerked in fear. “DRINK. YOU MUST STAY HYDRATED TO GET YOUR ENERGY UP. AFTER ALL THAT LEECH IS TAKING A LOT FROM YOU.” 

It was the nicest way the captain had ever told him to take of himself but all Sans could think was that he knew about the child. 

Papyrus never hid his hate for the former queen of a kinder world and the only reason he had no made true moves to kill her was that she was an extremely capable fighter and that Sans would undoubtedly join her side should the fight arise. 

A bony arm wrapped around the small soul protectively, “boss, please, i can leave right now. i was going to wait until tori came here but i swear if you let me go you’ll never have to see me again.” 

Papyrus rolled his eyes. “IF I WANTED YOU TO DIE YOU’D BE DUST BY NOW. I DIDN’T HEAL YOU AND DRAG YOUR SORRY ASS BACK HERE JUST TO HAVE YOU SPOUT OFF THAT KIND OF BULLSHIT. THAT GOAT CAN’T STAY HERE LONGER THAN A WEEK AT MOST AND YOU SURE AS HELL CAN’T GO THERE WITH THAT PATHETIC AMOUNT OF MAGIC YOU HAVE LEFT.” 

Gears turned in San’s head as the words sunk in. His brother the Great and Terrible Papyrus head of the Royal Guard who had been hand-picked by the feared King Asgore had not only spared him but healed him as well. 

If this had taken place at their home Sans might have understood it as using him as a potential bargaining chip against Toriel when she undoubtedly went looking for him.

But it had been far away from home and while he knew Papyrus could heal minor injuries when they were young, part of him thought that the ability had disappeared with LV gained.

Then there was the fact he had probably carried him here which showed all kinds of weakness that a plethora of monsters would try to exploit.

Sans blinked back tears, and it had all been for him the useless brother who couldn’t breathe to hard without fear of falling. “why?”

His voice was shaky and Papyrus found he couldn’t meet the others eyes. “I HAVE NOT SPENT ALL THESE YEARS TRAINING TO BE THE STONGEST OF ALL JUST TO LET YOU DIE BECUASE OF IT.” 

A sniffle had him look at the smaller skeleton who was vainly trying to wipe away tears. 

“sorry boss, hormones acting up i guess. you really are the coolest.”

**Author's Note:**

> I may make more.


End file.
